1. Technical Field
The present invention provides an image processing apparatus that generates a print image based on print data including a plurality of layers, and a computer readable storage medium stored with a control program of the image processing apparatus.
2. Description of Related Art
In the past, when a single display image is generated by combining objects drawn in a plurality of layers, a method has been employed in which priorities of object units are preset and objects are overlapped so as to preferentially display objects having higher priority (see the Japanese unexamined patent application publication No. Hei9-288477, and No. Hei7-73287). In this regard, the Japanese unexamined patent application publication No. 2005-77522, and No. 2009-282716 propose a technology that generates a display image in consideration of transparency of each layer when objects drawn in different layers overlap each other. The Japanese unexamined patent application publication No. 2004-9421 proposes a technology that when a template print based on an image captured by a digital camera is performed, transparency information (mask pattern) is set to a template image including a frame or “emoji”, etc., and the captured image and the template image are combined according to the transparency information.
By the way, when print processing of image data including a plurality of layers is performed, optimization processing (for example, thinning processing or edge enhancement processing) according to an attribute of each pixel is preferably performed. According to the conventional method, there is a problem in that objects of layers located at lower layers are not appropriately represented because only attribute information of the uppermost layer is referred to with respect to the pixel in which objects of different layers overlap each other. For example, when the uppermost layer corresponding to a certain pixel is a translucent image and a next layer is a text, an image object is subjected to optimization processing, but a text object is excluded from the optimization processing. Therefore, the image quality of the text object is relatively degraded.